A standardized test has been conducted to compute the compressive strength of two brands of cements. Fourteen cubes of cement 1 were tested by crushing them under a hydraulic press. Fifteen cubes of cement 2 were tested under similar condition. The cubes of cement 1 gave an average compressive strength of 59.4 MPa with a sample standard deviation of 7.8 MPa, while the cubes of cement 2 gave an average of 55.8 MPa with a sample standard deviation of 8.2 MPa. Can we conclude at the 0.05 level of significance that the compressive strength of cement 1 exceeds that of cement 2 by more than 2 MPa? Assume the populations to be approximately normal with equal variances.

MATLAB: An Introduction with Applications
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A standardized test has been conducted to compute the compressive strength of two brands of cements. Fourteen cubes of cement 1 were tested by crushing them under a hydraulic press. Fifteen cubes of cement 2 were tested under similar condition. The cubes of cement 1 gave an average compressive strength of 59.4 MPa with a sample standard deviation of 7.8 MPa, while the cubes of cement 2 gave an average of 55.8 MPa with a sample standard deviation of 8.2 MPa. Can we conclude at the 0.05 level of significance that the compressive strength of cement 1 exceeds that of cement 2 by more than 2 MPa? Assume the populations to be approximately normal with equal variances.

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